The Mentos in Diet Coke experiment has been a craze for several years now. Why so much appeal? The popularity stems from the simplicity of the experiment, the ease of the setup and the ability to preform it at home. Families and friends all over love watching the geyser that is created from a popular sweet candy and a world renowned soda. The Mythbusters from the Discovery Channel found that the reaction is caused by a something called nucleation. The CO2 in the soda enters microscopic pockets on the surface of the Mentos. The CO2 then turns into gas and bubbles to the surface. Meanwhile this is happening millions of times on the rest of the Mentos’ surface. The extensive bubbling causing the rocket of liquid that you see. To confirm their findings they took a Mentos that was coated so that the surface had no pockets. Just like they thought, there was little to no reaction. In our research we found that there was little study on the effect of temperature on the Diet Coke and Mentos reactions, and as a result we decided to test how different temperatures affect the reaction.
Procedure
Firstly, we made sure that there was a difference in temperatures between the five 2-liter bottles of Diet Coke. In ascending order, the Diet Coke bottles contained temperatures of 5, 10, 15, 20, and 30 degrees Celsius, in hope that they would show a clear linear relationship during our data analysis. Additionally, in order to create this different temperatures for the Diet Coke bottles we either immersed them in water baths at that specific temperature or we placed them in a refrigerator for the appropriate time necessary. Most importantly, in order to decrease fluctuations in the temperature from the time measured to the time tested, we made sure to measure the temperature of the Diet Coke quickly, then move it to a safe, secure testing location as quickly as possible, then measuring once more right before testing.
Once the bottles were set to the right temperature (any order is acceptable), we began testing the height of the mint flavored Mentos and Diet Coke reaction. It is important to buy the mint flavored Mentos, because it will cause the greatest reaction. Separately, we took each bottle to a safe, secluded location and anchored the bottle by surrounding it with bricks (other anchoring devises are acceptable as well). After the bottle was secure and stable, we filled a "Geyser Tube" (as seen and sold on stevespanglerscience.com.) with eleven Mentos and fastened it on top of the Diet Coke bottle. Before each reaction, we made sure that a computer with a camera was in position to capture the full height of the “Coke Geyser” reaction. This included positioning a meter stick at the same distance the Diet Coke bottle was from the camera. Once everything was in position, we hit "capture image" on the application LoggerPro (preferably) or any other video capturing devise and pulled the string on the "Geyser Tube" to release the Mentos into the Diet Coke and begin the reaction. We repeated these instructions with each 2-liter bottle, recorded our data and analyzed the data using the application "LoggerPro."
Results
From the data on the table below, we concluded that there was a direct relationship between temperature and the height of the reaction. The height of the reaction increased tremendously from the temperatures between 15 and 20 degrees Celsius. Even in the greater temperatures as the temperature continued to increase, the height of the reaction increased as well. This experiment was successful because we were able to obtain evidence on the data table below that clearly shows a direct relationship between temperature and the height of the Diet Coke and mint flavored Mentos reaction.
Temperature (Celsius)
Height of Reaction (Meters)
5
0.2355
15
0.6341
20
2.2890
25
3.265
29
3.936
Correlation Coefficient for Tempurature vs. Height: 0.9550
Conclusions
Sources of error include the distanced positioning of the computer in relation to the testing site, as this made it difficult for us to pinpoint the reaction heights while analyzing each video on the application LoggerPro. Also, errors include the loss of carbon dioxide that was released when we removed the cap of the coke bottle in order to measure the temperature of the diet coke and during the time when we were dropping the Mentos into the bottle. Additionally, I realized that the positioning of the Diet Coke bottle is very important to the experiment as well. Although I think we did a good job in placing the bottle completely upright, there could be a source of error in the height of the reaction if the bottle was tilted to the side even the slightest bit.
After much discussion, we would like to know if there is a maximum height of the reaction as temperatures increase. Since our results don't show a capping point, we can only assume that the reaction reaches a maximum height after the Diet Coke reaches a certain temperature. This would provide us with data to create a quadratic graph, which would be a good resource for students who would proceed with this experiment in the future to be informed of the maximum height at a specific temperature.
Table of Contents
Coke Geyser
Christian Olsen, Gabe Monett
Introduction
The Mentos in Diet Coke experiment has been a craze for several years now. Why so much appeal? The popularity stems from the simplicity of the experiment, the ease of the setup and the ability to preform it at home. Families and friends all over love watching the geyser that is created from a popular sweet candy and a world renowned soda.The Mythbusters from the Discovery Channel found that the reaction is caused by a something called nucleation. The CO2 in the soda enters microscopic pockets on the surface of the Mentos. The CO2 then turns into gas and bubbles to the surface. Meanwhile this is happening millions of times on the rest of the Mentos’ surface. The extensive bubbling causing the rocket of liquid that you see. To confirm their findings they took a Mentos that was coated so that the surface had no pockets. Just like they thought, there was little to no reaction. In our research we found that there was little study on the effect of temperature on the Diet Coke and Mentos reactions, and as a result we decided to test how different temperatures affect the reaction.
Procedure
Firstly, we made sure that there was a difference in temperatures between the five 2-liter bottles of Diet Coke. In ascending order, the Diet Coke bottles contained temperatures of 5, 10, 15, 20, and 30 degrees Celsius, in hope that they would show a clear linear relationship during our data analysis. Additionally, in order to create this different temperatures for the Diet Coke bottles we either immersed them in water baths at that specific temperature or we placed them in a refrigerator for the appropriate time necessary. Most importantly, in order to decrease fluctuations in the temperature from the time measured to the time tested, we made sure to measure the temperature of the Diet Coke quickly, then move it to a safe, secure testing location as quickly as possible, then measuring once more right before testing.Once the bottles were set to the right temperature (any order is acceptable), we began testing the height of the mint flavored Mentos and Diet Coke reaction. It is important to buy the mint flavored Mentos, because it will cause the greatest reaction. Separately, we took each bottle to a safe, secluded location and anchored the bottle by surrounding it with bricks (other anchoring devises are acceptable as well). After the bottle was secure and stable, we filled a "Geyser Tube" (as seen and sold on stevespanglerscience.com.) with eleven Mentos and fastened it on top of the Diet Coke bottle. Before each reaction, we made sure that a computer with a camera was in position to capture the full height of the “Coke Geyser” reaction. This included positioning a meter stick at the same distance the Diet Coke bottle was from the camera. Once everything was in position, we hit "capture image" on the application LoggerPro (preferably) or any other video capturing devise and pulled the string on the "Geyser Tube" to release the Mentos into the Diet Coke and begin the reaction. We repeated these instructions with each 2-liter bottle, recorded our data and analyzed the data using the application "LoggerPro."
Results
From the data on the table below, we concluded that there was a direct relationship between temperature and the height of the reaction. The height of the reaction increased tremendously from the temperatures between 15 and 20 degrees Celsius. Even in the greater temperatures as the temperature continued to increase, the height of the reaction increased as well. This experiment was successful because we were able to obtain evidence on the data table below that clearly shows a direct relationship between temperature and the height of the Diet Coke and mint flavored Mentos reaction.
Conclusions
Sources of error include the distanced positioning of the computer in relation to the testing site, as this made it difficult for us to pinpoint the reaction heights while analyzing each video on the application LoggerPro. Also, errors include the loss of carbon dioxide that was released when we removed the cap of the coke bottle in order to measure the temperature of the diet coke and during the time when we were dropping the Mentos into the bottle. Additionally, I realized that the positioning of the Diet Coke bottle is very important to the experiment as well. Although I think we did a good job in placing the bottle completely upright, there could be a source of error in the height of the reaction if the bottle was tilted to the side even the slightest bit.
After much discussion, we would like to know if there is a maximum height of the reaction as temperatures increase. Since our results don't show a capping point, we can only assume that the reaction reaches a maximum height after the Diet Coke reaches a certain temperature. This would provide us with data to create a quadratic graph, which would be a good resource for students who would proceed with this experiment in the future to be informed of the maximum height at a specific temperature.
References
Soda and Candy Eruption. 2011. Wikipedia, 31 January 2011. <http://en.wikipedia.org/wiki/Soda_and_candy_eruption>
The 'MythBusters' Take on the Mentos/Diet Coke Craze. 2001. Zap2it, 31 January 2011.
<http://www.zap2it.com/tv/news/zap–mythbustersmentos,0,4325641.story>
Mentos Diet Coke Geyser. 2005. Steve Spangler Science, 31 January 2011.
<http://www.stevespanglerscience.com/experiment/original-mentos-diet-coke-geyser>